We have been investigating the relationships between stress, immunity, and health, particularly as applied to cytokine imbalances. Initial studies revealed a primary switch from type 1 to type 2 cytokine imbalances in otherwise normal medical students as a function of exam stress. Laboratory tasks can also produce transient psychological and physical changes. The purpose of this study is to assess the psychological and physical effects of different tasks in a laboratory based model. Specific objectives of the proposed research are: 1. Characterization of the psychological and physiological effects that breaking bad news has on fourth-year medical students. Changes in mood, and immune, endocrine, and cardiovascular function will be assessed. 2. Examination of variables that are associated with the psychological and physiological effects of breaking bad news. The association between confidence in breaking bad news, method of breaking bad news, sympathetic nervous system arousal and the psychological and immunological effects of breaking bad news will be determined. We have assessed the psychological and physiological response of fourth-year medical students while they prepare for and deliver bad news in a simulated physician-patient scenario using a three group randomized controlled design. Participants will be randomly assigned to either: 1) a group delivering bad news; 2) a group delivering good news; or 3) a control group. By including a group that delivers good news we control for the stressful evaluator aspects of the situation, and the control group will control for the passage of time. Dimensions of response to the task include measures of mood and self-efficacy, and immune, endocrine, and cardiovascular function. We also assess the audio and video tapes on a number of parameters including use of open-ended questions, establishment of rapport, and empathic responses. Subjects are asked to ""role-play"" a physician conducting a 15 minute breaking bad or breaking good news interview with a simulated patient. Both the subject and the simulated patient are given a script to work from. The breaking bad news scenario will be one of a cancer patient who is about to hear the diagnosis of their terminal disease. The breaking good news scenario is one of a patient who is about to hear that their tests all came back negative for cancer. The subject then discusses follow-up care and lifestyle issues. Care will be taken to ensure that the participants speak for similar amounts of time in both scenarios. Subjects in both conditions are told that they are not being evaluated on their medical knowledge or the content of the interview, but rather on their communication technique. Participants assigned to the control group are asked to read magazines for the duration of the task period. Stress is best measured with a convergence of mood, physiological, and biochemical measures. The proposed research uses this approach to stress assessment, measuring changes in mood and physiological arousal indexed by catecholamine and cortisol levels and vital signs. Mood is assessed using the Profile of Mood States, a mood adjective check-list. Blood pressure and heart rate are measured throughout the study to provide a measure of cardiovascular reactivity during the task period. Stress-induced endocrine changes assessed in the laboratory provide a more objective assessment of stress than the typical self-report indices. Catecholamine and cortisol assays are conducted using plasma samples. Patients report on foods eaten during the sampling period, smoking, consumption of coffee and alcohol, and medications. These measures will be used as covariances in analysis of BP and endocrine data to control for possible sources of error. Immune function will be assessed between 7 and 11 AM to control for diurnal variation. Peripheral blood mononuclear cells (PBMC) will be harvested from heparinized venous blood and assessed for natural killer (NK) cell numbers, NK activity and mitogen-induced cytokine generation from cell cultures. Cytokine levels will be determined by antibody-sandwich ELISA using paired antibodies for IFN-g, IL-4, IL-10 and IL-12.